The app contains 4 microservices:
- Subscriber (sub) for (un)subscribing users.
- Gateway (gw) for mapping HTTP -> GRPC requests and entry point purposes. It's autogenerated with go-grpc-gateway
- Mailer - service for sending daily emails. Has cron job to trigger email once a day at 12:00 UTC (15:00 by Kyiv time)
- RateWatcher (rw) - service for getting the latest currency exchange rates
- Shared package (pkg) - pkg containing code, which can be used accross modules (logger setup etc.)
As per the task, I need to send a link to only one repository, it was decided to use go workspaces to fit all microservices to one repo. Typically, it should not be the case and it's antipattern. Basically, you can treat each top-level directory as a separate and independent repository/package/module. The protos top-level directory is also a go module, containing grpc-generated code.
- GO as a main programming language
net/httpfor HTTP server- GRPC for inter-service communication
log/slogas a structured logger- swaggo for generating swagger documentaion
- MySQL as a database
- Golang migrate for DB migrations
- Gomock for mock generation
https://drive.google.com/file/d/1jrEaqvzlhKB4HB98VEykbiR00G2OEwJS/view?usp=sharing
- Copy .env.example contents to .env
- Get a token for exchange rate API (https://app.exchangerate-api.com/)
- Populate the
EXCHANGE_API_KEYvariable value with the token you've got - Get a token for resend API (https://resend.com/)
- Verify your domain for sending
- Populate the
MAILER_API_KEYvariable value with the token you've got - Populate the
MAILER_FROM_ADDRvariable with the email you've verified - Populate other variables, such as
MAILER_SMTP_FROMetc. - From the root of the repo run
docker compose up -d
The repository contains root taskfile which imports other task files specific to each service. To see all available commands just type:
taskYou should get the following output, where each line is the name of the task:
* default: Show available tasks
* lint:
* test:
* gw:generate: Generate (used for mock generation)
* gw:install: Install all tools
* gw:install:gofumpt: Install gofumpt
* gw:install:lint: Install golangci-lint
* gw:install:mock: Install mockgen
* gw:lint: Run golangci-lint
* gw:run:
* gw:test: Run tests
* gw:test:cover: Run tests & show coverage
* gw:test:race: Run tests with a race flag
* mailer:generate: Generate (used for mock generation)
* mailer:install: Install all tools
* mailer:install:gofumpt: Install gofumpt
* mailer:install:lint: Install golangci-lint
* mailer:install:mock: Install mockgen
* mailer:lint: Run golangci-lint
* mailer:run:
* mailer:test: Run tests
* mailer:test:cover: Run tests & show coverage
* mailer:test:race: Run tests with a race flag
* protos:generate:
* protos:generate:mailer:
* protos:generate:rw:
* protos:generate:sub:
* rw:generate: Generate (used for mock generation)
* rw:install: Install all tools
* rw:install:gofumpt: Install gofumpt
* rw:install:lint: Install golangci-lint
* rw:install:mock: Install mockgen
* rw:lint: Run golangci-lint
* rw:run:
* rw:test: Run tests
* rw:test:cover: Run tests & show coverage
* rw:test:race: Run tests with a race flag
* sub:generate: Generate (used for mock generation)
* sub:install: Install all tools
* sub:install:gofumpt: Install gofumpt
* sub:install:lint: Install golangci-lint
* sub:install:mock: Install mockgen
* sub:lint: Run golangci-lint
* sub:run:
* sub:test: Run tests
* sub:test:cover: Run tests & show coverage
* sub:test:race: Run tests with a race flagThey're quite handy to run tests/linters/formatters or to generate grpc-related code and they will install all the deps in case you don't have them.
Before committing anything, you need to also install left-hook. It will run golangci lint before committing to prevent common dummy issues related to formatting/go code. Typically, it should be covered by the CI job, but I need to reduce possible extra runs, considering GH actions has limit on daily runs.
Compose file has definition of 4 microservices + 1 db service (MySQl) + migrator service (used for running DB migrations on startup). Typically, services won't start till DB is up and migrations has succeeded. So, keep in head, that startup could take some time (1-2 minutes). Data is saved in volume and pods communicate using shared private network. The only pod, which port is mapped to the host port is gateway service.
Services are perfectly documented with Godoc comments. You can host godoc server running following command from the root of the repo:
task godocThen you can visit http://localhost:6060/pkg/github.com/hrvadl/converter/?m=all and see documentation for all my packages
The application uses GI actions (free tear) as a CI runner. It suits perfectly for small non-commercial projects. CI heavily relies on the taskfile to do its job. This means each CI step could easily be run locally. CI steps are run in parallel to reduce the time spent waiting for the results.
